Beam compass



. J. CLARK BEAM coMBAss Nov. 24, 1942.

Filed neo, 18, 1941 2 sheets-shed `1 ...Nfwm N Patented Nov. 24, 1.942

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" 2,303,024 f p v t I i BEAM-'1 CoMPAss 'l AJesse. Clark, Los Angeles, alif. n v Application December 11s, 1941, semina. `423,550

s claims. (c1. `:s-frz). This invention relates toa""beam compass of very simple construction capable of j being ,eco` nomical'ly"manufactured"and which, though'very light` in weight, is' very durable;

' MoreV particularly, it` isJ an aim cf' the inven' tion to provide'a beam compass' of whi-ch'a beam ca'nbe formed by a yard stick, ora number of yard'sticks connected in end to end relationship: so-thatV the instrument can be` extendedto great lengths.

. Still Aa further aimof the'invention is to pro vide' anl instrument of the above describedcharm acter/ wherein the" ruling pen or pencil is supe ported at" substantially a right'angleto the sur# face on whichthe mark is made. l Y Other vobjectsa and advantages of-I the invention will hereinafter become more fully apparenty from the following description of the drawings, which illustrate a preferred embodiment thereof, and wherein:

Figure lis a fragmentaryVV side elevational-view' of the instrument,

Figure 2 isatop plan View of the same,

Figure 3 is an enlarged fragmentary bottom plan View of the same, A y

Figure 4 is a transverse vertical sectional view taken substantially along the plane of the line 4-4 of Figure 1,

Figure 5 is a longitudinal horizontal sectional view taken substantially along the plane of the line 5-5 of Figure 1,

Figure 6 is a fragmentary sectional view of a portion of the instrument taken substantially along a plane as indicated by the line ,6-6 of Figure 4, and

Figure '7 is a vertical sectional view taken substantially along the plane of the line 'I-l of Figure 2.

Referring more particularly to the drawings, wherein like reference characters designate like or corresponding parts throughout the different Views, I2 designates generally the beam compass in its entirety and Which includes a beam I I and two supports I2 and I3 which are slidably mounted thereon. The beam II is preferably a conventional yard stick.

The slide support I2 includes an inverted U-shaped base I4 of metal which engages over the beam II and extends downwardly below the bottom edge thereof. A plate I5 is secured to one of the legs or sides I6 of the base I4 which has one end rolled outwardly to form a spring sleeve I1. A plate I8 is secured to the outer side of the other side of the legs I6. 'I'he plates I5 I. The sleeve I'I exposesv one end vI2 and the oppositelendther'eof has itslower and intermediate portions bevelledV the lever 23 ispro'vide'd'with an enlarged'rounded end or edge and' Visprovided with an opening 24 which 1 is e'ccentrically 'disposed l relatively to" said edge' 25. vThe enlarged end of the lever 23 Vis disposed between theV sides It and below the' beam" II and thebolt 20 extendsloesely' through the opening 24' forv swingably mounting the lever. The op'po'site',"free end of the'` lever 23 extends outwardly from the bottom edge or the' tapered edge" Iviofthev slide I2' and has a st'o'pI piri`2SeX-- tending therethrough and beyond the sides" thereof yto preventtherfreelend ofthe vlever 23' fromA swinging' into 'a position be tween the" sides I6. By swinging the'free end of the lever 23 in a counter-clockwise direction,l as seen in Figures 1 and 6, a portion of the edge 25 thereof will f move into engagement with the bottom edge of the beam II and by a cam action will force the beam upwardly for clamping it between the edge 25 and the intermediate portion of the base I4 for clamping the slide support I2 to the beam II. A thumb nut 2l is in threaded engagement with the shank end of the bolt 20 and is adapted to be tightened for clamping the lever 23 in either a released or an applied position.

The slide support I3 also includes an inverted U-shaped'base 28 of metal which engages over the Vbeam II. One of the sides 29 of the base 28 is provided at its outer end with an extension 40 having an outturned substantially perpendicular ange 30. An angle bar 3| is suitably secured to said side 29 and has one side projecting outwardly therefrom and disposed substantially parallel to the flange 30 to combine therewith to form a substantially perpendicular channel adapted to receive a tube 32 which is secured to the flange 30 and the bar 3I as by means of soldering, not shown. The tube 32 has an internally threaded upper end 33 for receiving a threaded plug'34,

for a purpose that will hereinafter be described. In all rother respects, the base 28 corresponds to the base I4 and is provided with a tapered inner edge I 9 corresponding to the inner edge I9 of the base I4. The sides 29 are reinforced by triand I8 provide renforcing'means for the sides 55 angular plates 35 whichare secured to the outer f the situ;

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sides thereof. The plates I5, I8 and 35 are preferably attached by means of soldering. The slide support I3 is provided with a cam lever 23 mounted by means of the bolt 20 in the same manner and for the same purpose as the lever 23 of the slide I2, and a further description of these parts is therefore considered unnecessary.

The sleeve I1 and the tube 32 are disposed at the remote ends of the slides I2 and I3, respectively, and are disposed on the same side of the beam II. The sleeve I1 is adapted to frictionally support an inscriber 36, such as a pencil, or a ruling pen, which can be Wrapped with paper to enlarge it sufliciently so that it can be engaged and held by the sleeve I1. The tube 32 is adapted to frictionally engage a stylus 31, the pointed end thereof projecting below the lower end of the tube. The plug 34 is provided to prevent the stylus 31 from being forced upwardly through theA tube. It will thus be readily apparent that the pointed lower end of the' stylus 31 can be used as a pivot and the pointed lower end or marking end of the inscriber 36 canl then function to inscribe an arc or circle when the beam compass I0 is revolved on its pivot. It will be obvious that the vbeam compass IIJ can =be extended to great lengths and a beam longer than a yard stick may be employed, if required, and such a beam is readily provided by connecting a number of yard sticks in end to end relationship. Furthermore,

- the beam compass IIJ is more practical than the ordinary hand compass as the pivot and the inscriber are both at right angles to the work. For very close work, the supports I2 and I3 can be reversed so that the sleeve I1 and the tube 32 will be adjacentlydisposed.

As a modification of the beam compass I0, two of the slide supports I3 could be employed, each of which would carry a stylus 31 to provide a compass which would be lighter, better balanced and of a greater range than trammels now used by lay out men in sheet metal shops.

Various other modifications and changes are contemplated and may obviously be resorted to, provided they fall within the spirit and scope of the invention as hereinafter dened by the appended claims, as only a preferred embodiment `of the invention has been disclosed.

I claim as my invention:

1. A beam compass comprising a supporting beam, a pair of slides mounted for sliding movement relatively to one another on the supporting beam, a cam member carried by each slide, said cam members being movable into positions for clamping the slides to the supporting beam, one of the slides having means adapted to mount an inscriber, and the' other slide having means adapted to support a stylus, said cam members each including an eccentrically mounted lever, a. bolt forming the pivot of the cam member, and a nut, carried -by the bolt, for clamping the cam member in adjusted positions.

2. A beam compass comprising a supporting beam, a pair of slides mounted for sliding movement relatively to one another on the supporting beam, a cam member carried by each slide, said cam members being movable into positions for clamping the slides to the supporting beam, one of the slides having means adapted to mount an inscriber, and the other slide having means adapted to support a stylus, said last mentioned means comprising a tube, said tube being secured to the last mentioned slide, and a closure removably mounted in one end of the tube.

3. In a beam compass, a support adapted to slidably engage a beam, said support having an inverted U-shaped base portion, said portion being slidably mounted on the beam having sides, formed of a plurality of plies, extending below the lower edge of the beam, clamping means carried by the lower ends of said sides for clamping the base portion to the beam, and the outer ply of one side of the base portion having a portion rolled to form a spring sleevefadapted to detachably mount an inscribenv JESSE CLARK. 

